Process for solvent extraction of mineral oil



y 194L' D. R. MERRILL ErAI. 2 ,373

PROCESS FOR SOLVENT EXTRACTION OF MINERAL OIL Filed Nov. 12, 1932 3Sheets-Sheet 1 DICHLOR- OIL ETHYL CONTAINING ETHER wAx HEATING R REXTRACTION 8? RAF'FINATE EXTRACTION I- a No. 1; 8 RAFFINATE v ARAFSINATE OIMWAX Q WAX No.1, 1N No.1,

ETI-IER NA ACETONE, NA WAX NOJ, PROPANE GT PROPANE GT PROPANE E E vRECOVERED EXTRACT PROPANE EXTRACT +1 ,LlQilD PROPANE DISTILLATIONzx'I-IzAc'ruozA E SATION a; WAX No. 3A, ACETQNE RAFFINATE E5 ACETONENo.1 111mg v 83: I UID A L Q 355 PROPANE L D.- J n EXTRACTION R R 8% CAEXTRAGT No.1 F RAFFINATE 8; RAFFINATE No.2, u RAFFINATE No 2 WAX wAx NO2 No.2, PROPANE ETHER, x AcE-rouEj I [5; WAX NO. 2, PROPANE, GT PROPANEE PROPANE v E Ls mum E EXTRACT PROPANE EXTRACT NO-SA, V DISTILLATION.ACETONE. j Y

[EXTRACTION r RAFFINATE WAX EXTRACT COOLIN e SI- 1:2

WAX RAFFINATE No.3,

ETHER' wAx No.3,

ACETONE PROPANE RAFSgIQTE PRoPANE EXTRACT RECOVERED I J ACETONE PROPANEI DISTILLATION g EITHER ACETONE. CONDENSATION CONDENSATION Y RAFFINATEZ) 'dRM 7/ Pfi l lt avz e r:

EXTRACT ETI-IER r g l ub ow NO. E & Ex'rRAc'r BY I, I i rfiiz I v r I IA ATTORNEY ,3 Sheets- Sheet 2 July 8, 1941. o. R. MERRlLL ETAL PROCESSFOR SOLVENT EXTRACTION 0F MINERAL OI L Filed Nov. 12, 1932 y 1941- D. R.MERRILL El AL .2 3

PROCESS FOR SOLVENT EXTRACTION OF MINERAL OIL Filed Nov. 12, 1932 3Sheets-Sheet 3 QQN Am\ Mm 3w mmw \ww un MWN Pu (1.5a

MWN WMN www MN MN MPENEdmW mmN ms mm ATTORNEY. I

Patented July 8, 1941 UNITED STATES PATENT OFFICE P RtOCESS FOR SOLVENTEXTRACTION F 1 MINERAL 01L David B. Merrill, Long Beach, and PhilipSubkow,

Los Angeles, Calif., assignors to Union Oil Com-- pany of California,Los Angeles, Calif., a cornotation of California Application November12, 1932, Serial No. 642,371

13 Claims.

extracted in the next succeeding zone with a selective solvent and theextract phase coming The heavy oil fractions of many crude oils,

from which lubricating oils are produced, consist of a mixture ofhydrocarbons some of which exhibit a low temperature viscositysusceptibility and some of which exhibit a high temperature viscositysusceptibility. In order to produce superior lubricating oil from suchhydrocarbon mixtures, those oils present having a high viscositytemperature susceptibility are separated from the oils present whichexhibit a low temperature viscosity susceptibility. Solvent extractionis one of the methods employed to separate the undesirable oil from thedesirable oil. Solvents, such as aniline, furfural, nitrobenzene,selenium oxychloride, sulphur dioxide or dichlorethyl ether are capable,under the proper conditions of temperature and pressure, of dissolvingthe fractions present which are non-paraflinoid in character. Thesesolvents form relatively heavy solutions with the nonparaflinoid oilfractions and can be separated from the insoluble parafflnoid oilfractions by settling. That portion insoluble in the extracting solventis termed the railinate while the soluble portion is known as theextract.

In the following disclosure of our process, wherever dichlorethyl etheris mentioned it will be understood that the other solvents recited abovemay likewise be employed. B B dichlorethyl ether, ClCHzCHzOCHaCHzCl, hasa preferential solvent action on aromatic or non-paraflinoid componentsof the oil. However, we have found that when extraction is accomplishedusing this solvent, not all of the paraflinoid components are removed inthe insoluble raiiinate, nor are all of the non-paraiilnoid componentsdissolved in the extract. In other words, the solvent is selective as toa large proportion of parafl'lnoid and nonparafilnoid components but itsselectivity is not entirely complete. We have found that after theprimary separation .by extraction with dichlorethyl ether, the extractand raiiinate may be further classified separately whereby the ramnatewill in turn be divided into a second rafilnate and a second extract andwherebythe primary extract may be divided into another extract andanother raflinate.

We have found that in the operation of our process we are able to obtaina rafiinate of very high quality, 1. e., having a large'proportion ofparaflinoid components and to obtain additional raliinates havingsuccessively smaller proportions of paraflinoid components as well as toobtain an extract high in the proportion of non-paraflinoid fractions.We have also found that temperature conditions during these extractionsexert a great influence upon the character of the materials comprisingthe rafiinate and extract. For instance, when the primary extraction iscarried out at a relatively high temperature we have found, uponreduction of temperature of the solution of dichlorethyl ether andextract obtained from said primary extraction, that this extract may inturn become separable into two phases, a raflinate and an extract. Thislatter extract may again be treated similarly after another reduction intemperature and this process can be continued to produce as manyintermetract to produce fractions having various propor-' tions ofparaflinoid components. 4

-When the primaryextraction with dichlorethyl ether is accomplished atrelatively high temperatures, i. e., about 100 F. or more, the raflinateproduced has a desirable large proportion of nonparaflinoldhydrocarbons, but the yield of this raflinate is small. Commercialoperation necessitates further extractions at lower temperatures.

1. e. 40 F. or 0 F., to obtain larger yields. In the extraction ofcertain oils with dichlorethyl ether, alone, it is sometimes found thatthe millnate is a viscid mass at the temperature necessary forextraction. This is particularly true when 'a wax-containing oil issubjected to' such treatment. We have found that the presence of a lighthydrocarbon, such as a petroleum fraction obtained by the rectificationof natural gasoline, reduces the viscosity of this mixture whereby moreefiicient stratification and separation are accomplished.

As an example of such commercially available fractions, one composed of6.72%, ethane, 72.2%

propane, 19.91% isobutane and 1.17% normal butane may be cited assatisfactory. It will be understood, however, that these merelyillustrate the type of fractions which may be ,used and that thecomposition may vary. This fraction will hereafter be referred to aspropane for purposes of simplicity. Also, in the operation of ourprocess in which the raflinate from the primary extraction is furthercooled in the presence of acetone for additional extraction, theviscidity of this rafllnate may likewise be reduced by the addition ofliquid propane.

We have also found that the presence of seetone in the furtherdichlorethyl ether extraction at lower temperatures of the extractproduced in the primary extraction at high temperatures is advantageous,not only for its own solvent effect, which is similar to that of thedichlorethyl ether, but also because of its diluent action and itsproperty of inhibiting the presence of wax in the extract phase.

The pressure to be employed in the operation of our process depends upona number of factors, notably the temperature used and the amount ofsolvents employed. However, the pressure should be sufiicient toaccomplish the extraction while these solvents are liquid.

Therefore, it is an object of our invention to obtain by solventextraction a number of fractions having varied proportions ofparaflinoid components from mineral oil such as lubricating oil forexample, which comprises parafllnoid and non-paraflinoid components.

Frequently such oil contains wax. It is a further object to dewax theoil in addition to treating it by successive extractions.

Another object is to correct for the lack of complete selectivity of thesolvent by further selective extractions either of the raflinate orextract produced by the primary extraction, or by further selectiveextractions of both this rafiinate and extract.

In the drawings,

Fig. 1 is a flow sheet of the principal steps involved in the operationof our process.

Figs. 2 and 2A are one form of apparatus which we may employ to carryout our process. The diagrammatic embodiments in Figs. 2 and 2A has beendivided along line 2-2.

Referring to Fig. 1 the flow of the material indicated by the legends isin the direction of the arrows. The raiflnate is that portion insolublein the extracting solvent. The extract is that fraction soluble in theextracting medium. Figs. 2 and 2A show in. greater detail the processoutlined in Fig. 1.

Referring more particularly to Figs. 2 and 2A,

oil containing wax to be subjected to treatment is stored in tank 5. Itis removed therefrom by action of pump 6 in line 1 controlled by valve 8and passes through calls 9 disposed in heater II]. From heater it thisoil passes via line H into line Ir. Dichiorethyl ether stored in tank 12is constricted apertures in diaphragms consecutively interposed betweenrelatively large chambers whereby intimate contact of the liquids isinsured. From the mixer I! the liquids pass via line l9 into primarysep'arator20 wherein the oil separates into two phases, a railinatesubstantially insoluble in dichlorethyl ether and an extract solubletherein. However, at the temperature employed, a. minor amount of theether may also be dissolved in the railinate.

This raflinate in separator 20 is removed therefrom by pump 23 in line2| controlled by valve 22. Acetone is introduced into line 2| by passagefrom acetone storage 25 through line 26, valve 21, pump 28, lines 29 and30, and valve 3|. The mixture is then passed through orifice'mixer 35,line 38 and line 31 for cooling by heat exchange in heat exchanger IIwith the material to be described below flowing through line 69. Theraflinate and acetone mixture then flows through line 39 into which isintroduced a stream of liquid propane. Propane, under pressuresufficient to be maintained in the liquid state, is stored in tank lland may be passed by action of pump ll into line 39 via lines l2 and 44controlled by valves 42 and Ii, respectively. The cooledrailinate-acetone-propane mixture containing a small amount ofdichlorethyl ether then passes through orifice mixer II and line 41 intoseparator 5| in which this mixture again separates into two.

phases; a rafiinate solution in propane substantially insoluble in thesolution of extract in aceeration of the ramnate containing wax. ,Jhewax,

will precipitate from the oil at the low temperature produced. Propanevaporized in chamber 53 passes therefrom via line 5! controlled by valve56 by action of pump l1 and thence into condenser coil 58 in which it isreturned to liquid condition. Liquid propane is recycled to storage 40by passage through line 59.

The mixture of rafiinate, precipitated wax and remaining propane inchamber 53 mayalso contain a relatively small proportion of dichlorethylether and acetone not removed in separators 2| and 50. This mixture in53 passes therefrom by action of pump 82 in line .3 controlled by valve64 into filter press 65 wherein the waxis retained on the filter plates,while the wax-free filtrate is removed via line 88 controlled by valve61. The wax remaining in filter may be removed by any usual method.

The cold wax-free filtrate from F5 is next forced by pump '88 through aseries of heat interchangers in order to raise its temperature beforedistillation of the remaining solvents from the oil. Accordingly, itpasses via line 66 into line 69 disposed in heat exchanger 38 to absorbheat from the material passing through line 31;

- thence via line into line II situated in heat exchanger 12 to absorbheat from the material to be described below flowing through line I22,thence via line 13 into line 14 disposed in heat exchanger 15 to absorbheat-from the material to be described below flowing through line I40.The preheated wax-free filtrate from filter press 65 is then introducedinto still 80 via line 16.

Distillation is eilected in 80 by introduction of additional heat; forinstance, byfiow of steam through closed coil 8|. The solvents arethereby removed from the raflinate which remains undistilled. Thiswax-free raflinate, therefore, is

that portionof the oil which is substantially insoluble in dichlorethylether and acetone. From column still 80 the wax-free rafiinate isremoved via line 82 and valve 93 by pump 84 into storage 65. Propane,together with any acetone and/or dichlorethyl ether present, vaporizesin still 60 and exits therefrom via line 86 controlled by valve 61.These vapors-pass into condenser coil 88 and thence into separator 90via line 89. Condensation of the acetone and ether is effected in- 86while the propane remains in vapor form. Propane vapors are removed from98 by pump 9I via line 92 controlled by valve 93 to line 55 for returninto liquid propane storage 80 in the manner above described.

Acetone and dichlorethyl ether are removed from separator 90 by pump 94in line 95 controlled by valve 96, Line 95 connects with still I00provided with closed steam coil IOI. Acetone vaporized in still I00escapes via line I02 controlled by valve I03 into condenser coil I06 andthe acetone is returned to storage 25 by action of pump I85 in line I06.Dichlorethyl ether, undistilled in still I00, passes to storage I2 vialine I81 and valve I86 by action of pump I09.

Returning now to separator 50, the extract solution in acetone anddichlorethyl ether is removed by pump III through valve II2 via line IIOwhich connects with line 200 through which flows a mixture describedbelow.

Again referring to primary separator 20, the extract soluble indichlorethyl ether is removed by pump II6 through valve H1 in line H5.Acetone may be introduced at this point by flow from storage 25 throughline 26, valve 21, pump 28, valve H8 and line H9. The mixture ofextract, ether and acetone is then intermixed in orifice mixer I afterwhich it passes via line I2I into line I22 situated in heat exchanger 12for cooling by heat exchange with the material described above flowingthrough line 1|. From the heat exchanger 12 the mixture flows throughline I23 into line I25 disposed in heat exchanger I24 to be cooled byheat exchange with the material described below flowing through lineI52. The cooled mixture then passes through line I26 into separator I30in which the mixture separates into two phases; a rafiinatesubstantially insoluble in dichlorethyl ether and acetone and an extractsoluble therein. The rafiinate may, however, contain a minor proportionof the ether and acetone.

Following the course oi the ramnate from separator I30, it is removed byaction of pump I3I into line I 32 controlled by' valve I33. Acetone maybe introduced into this line from storage 25 via line 26, valve 21, pump28, line I34 and valve I35. Liquid propanemay be sent into line I32 fromstorage 40 via line 42, pump 4|, valve 43, line I36 and valve I31. Themixture flowing through I32 is then intermingled by passage throughorifice mixer I36 from which it passes by line I39 into line I40situated in heat exchanger 15 in which it is cooled by heat exchangewith the material above described flowing through line 14. From heatexchanger 15 the mixture passes into line I into which is alsointroduced cold liquid propane from line I53.

The manner in which this cold liquid propane is obtained is as follows:propane from storage 40 passes via pump 4|, line 42, valve 43 into lineI42 through expansion valve I43 and into propane cooler I45 in which thepressure is sufiiciently reduced to partially vaporize the propane. Thispartial vaporization results in a drop in temperature in the liquidpropane remaining in cooler I45. Propane vapors are removed by pump I46via valve I41 in line I48 which connects with line 55 through which theypass for condensation and storage in 40 in the manner described above.Cold liquid propane is removed from cooler I45 by pump I49 through lineI50 controlled by valve I5I. This cold propane then passes through lineI52 disposed in heat exchanger I24. The material, previously described,flowing through line I25-is thus cooled by heat exchange with the coldliquid propane in line I52. The propane then flows through line I53which connects with line I4I, described above.

The cold mixture of propane and raflinate from separator I30 then isintermingled in orifice mixer I54 and flows to separator I55 via lineI56. Separation occurs therein into two phases; a raflinate'solution inpropane substantially insoluble in the dichlorethyl ether and acetoneand an extract soluble therein. The raffinate, however, may contain asmall proportion of ether and acetone as well as some wax which was notremoved in primary separator 20. This rafiinate is removed fromseparator I55 via line I51 controlled by valve I58 and is passed into.

expansion chamber I60. duced sufliciently therein to cause evaporationThe pressure is reof at least part of thepropane with consequentinternal refrigeration of the rafiinate containing wax. The wax willprecipitate from the oil at the low temperatures attained.

Propane vaporized in chamber I68 passes therefrom via line I6Icontrolled by valve I62 by action of pump I63 and thence into lines 92and 55 for condensation and return to liquid propane storage 40 as abovedescribed. The mixture of raifinate and precipitated wax and remainingpropane in chamber I60 passes therefrom by action of pump I64 in lineI65 controlled by valve I66 into filter press I 61 wherein the Wax isretained on the filter plates While the wax free filtrate is removed vialine I68 controlled by valve I69. The wax remaining in filter I61 may beremoved by any usual method.

The cold wax-free filtrate from I61 is next forced by pump "0- into lineI1I disposed in heat exchanger I 12 to raise its temperature by heatexchange with the material tobe described passing through line 205. Thefiltrate then passes through line I13 into column still I 15 heated byclosed steam coil I16. The raflinate is freed therein of acetone, etherand remaining propane by distillation. This rafiinate is removed by pumpI11 in line I18 controlled by valve I19 and passes into storage I08.

The acetone, dichlorethyl ether and propane vapors in still I15 issueinto line I83 controlled by valve I84 and thence pass into condensercoil I85. They are cooled sufficiently to condense the acetone andether. These materials pass by line I86 into separator I81 from whichthe propane vapors issue via line I88, valve I89 and pump I90 into linesNil, 92 and 55, as previously described, for liquefaction and recoveryof the propane. The condensate in separator I 81 comprising acetone anddichlorethyl ether passes through line I9I, valve I92 and pump I93 forpassage into line 95 and still I99, as previously described, for theseparate recovery of these solvents.

pump 243 into lines 2I8, I48 and 55 for liquefaction and recovery of thepropane as previously described. The condensate in separator 249comprising acetone and dichlorethyl ether passes through line 244, valve245 and pump 246 into line 95 and still I99 for the separate recovery ofthese solvents as previously described.

Again referring to separator -2I9, the extract solution in acetone anddichlorethyl ether is re- Returning now to separator I55, the extractsolution in acetone and dichlorethyl ether is removed by pump I95through valve I96 via line I9'I which connects with line 249 throughwhich flows a mixture described below.

Again referring to the separator I39, the extract soluble in acetone anddichlorethyl ether is removed by pump I98 through valve I99 in line 299.Acetone from tank 25 is introduced into this line by passage throughline 26, valve 21,

pump 28, line 29I and valve 292. Extract, previonsly described, fromseparator 59 is likewise introduced into this line via line 9, pump II Iand valve II2.

. The mixture in line 299 is then intermingled in orifice mixer 293 andis passed via line 294 into line 295 disposed in heat exchanger "2 to becooled by heat exchange with the medium described above flowing throughline Ill. The cooled extract in line 295 then passes via line 296 intoseparator 2I9 in which a separation of phases is accomplished. Theraflinate, i. e., insoluble portion containing wax not previouslyremoved-in separators 29 and I39, exits from separator 2I9 by action ofpump 2 in line 2I2 controlled by valve 2I3. Cold liquid propane, chilledin cooler I45 as previously described, 'is introduced into line 2I2 frompropane cooler I45 via pump I49, line I59, valve I5I, line 2 andrefrigeration whereby the wax will precipitate at the low temperaturesattained. Propane vaporized in chamber 2II passes therefrom via line 2|8 controlled by valve 2| 9 by action of pump 229 and thence into linesI48 and 55 for condensation and return to liquid propane storage 49 asabove described.

The mixture of raflinate, remaining propane and precipitated wax inchamber 2" passes therefrom by action of pump 22I in line 222 controlledby valve 223 into filter press 225 wherein the wax is retained on thefilter plates while the wax-free filtrate is removed via line 226controlled by valve 221 by action of pump 228 into column still 239heated by closed steam coil 23I. The raffinate is freed therein ofacetone, dichlorethyl ether and remaining propane by distillation. Thisraflinate is removed by pump 232 in line 233 controlled by valv 234 intostorage 235.

The acetone, dichlorethyl ether and propane vapors in still 239 issueinto line 236 controlled by valve 231 and thence pass into condensercoil 238. They are cooled sufliciently to condense the acetone andether. These materials pass via line 239 into separator 249 fromwhichthe propane vapors issue via line 2, valve 242, and

moved by pump 24] through valve'248 via line 249 into which issues thepreviously described extract from separator I55 via line I9I. The mixedextracts then pass via line 249 into column still 259 heated by closedsteam coil 25I. The extract is freed therein by distillation of acetone,dichlorethyl ether and any propane which may be present. This extract isremoved by pump 252 in line 253 controlled by valve 254 into extractstorage 255.

The acetone, dichlorethyl ether and propane vapors instill 259 issueinto line 256 controlled by valve 251 and thence pass into condensercoil :58. They are cooled sufliciently to condense the acetone andether. These materials pass via line 259 into separator 269 from whichthe propane vapors issue via line 25L valve 262, pump 263 into lines2I8, I48 and 55 for liquefaction and recovery of the propane, aspreviously described. The condensate in separator 259 comprising acetoneand dichlorethyl ether passes through line 264, valve 265 and pump 265into line and still I09 for the separate recovery of these solvents, asdescribed above. 7

It will be observed that in the operation of our process according tothe exemplary method recited above and according to the flow sheet, Fig.1, oil containing wax may be successively fractionated by solventextraction whereby several fractions having varied characteristics maybe obtained. For instance, if the oil to be treated is' a waxylubricating oil containing paraffinoid and non-paraifinoid components,the extraction with dichlorethyl ether in separator 29 fractionates theoil into a railinate having a relatively large proportion of paraflinoidhydrocarbons and into an extract having a large proportion ofnonparaflinoid fractions.

The paraifinoid content of this rafilnate is further increased by theextraction at a lower temperature in separator 59 in the presence ofacetone, propane and any dichlorethyl ether which may pass with theraflinate from separator 29. r

The raflinate from 59, after wax removal in filter 65 andafter'solventremoval in still 89, has

-the largest proportion of parailinoid components of any of thefractions obtained by ourprocess. It is stored in tank 85. v

The extract obtained by separation with dichlorethyl ether in separator29 is then subjected to a series of extractions for further separationof paraflinoid from non-parafilnoid components in the presence ofdichlorethyl ether, acetone and propane at successively lowertemperatures in separators I39 and 2I9. For instance, the tem- Theextract portions from separators 50 and I30 may be treated conjointly asdescribed above,

.or separately. The rafilnate from the extraction in separator2I|l,'after wax removal in filter 225 and after solvent removal in still230 contains the third'largest proportion of parafilnoid components. Itis stored in tank 235.

The extract phases from separators I55 and 2|!) may be treated together,as described, or separately. This extract, after removal of the solventsin still 250, contains theleast proportion of paraifinoid components andthe largest proportion of non-paraflinoid fractions. It is stored instorage 255.

It is to be understood that while the foregoing example relates tosuccessive solvent extraction of lubricating oil containing wax, ourinvention is not limited thereto because it is applicable to thetreatment of mineral oils and hydrocarbons both heavier and lighter thanlubricating oils. Furthermore, our invention is not limited to the samenumber of phase separations described but may be varied by omission ofthe extraction occurring in separator Zill or the number of separationsmay be increased if the need should arise. Many other variations may bemade without departing from the spirit of our invention.

We claim:

1. A process of separating paraifinoid and nonparafiinoid componentsfrom mineral oil which comprises mixing said oil with dichlorethylether, separating the extract soluble therein from the raffinateinsoluble in dichlorethyl ether, mixing said rafiinate with liquidpropane, reducing the temperature of said ramnate to separatesaidrafiinate into a second extract and rafiinate and separating saidsecond extract from said raifinate.

2. A process of separating parafilnoid and nonparamnoid components frommineral oil which comprises mixing said oil with dichlorethyl ether,separating the extract soluble therein from the rafiinate insoluble indichlorethyl ether, mixing said raflinate with acetone; and separatingthe extract soluble in said acetone from the ramnate insoluble therein.

3. A process of separating paraflinoid and nonparafiinoid componentsfrom mineral oil which comprises mixing said oil with dichlorethylether, separating the extract soluble therein from the rafilnateinsoluble in dichlorethyl ether, mixing said rafiinate with acetone,reducing the temperature of said rafiinate, and separating the extractsoluble in said acetone from the rafiinate insoluble therein.

-4. A process of separating paraffinoid and nonparamnoid components frommineral 011 comprising mixing said oil with dichlorethyl ether,separating the extract soluble therein from the ramnate insoluble indichlorethyl ethenmixing said rafiinate with liquid propane and acetone,and separating the extract soluble in said acetone from the raflinateinsoluble therein.

5. A process of separating paraflinoid and non parafi'inoid componentsfrom mineral oil comprising mixing said oil with dichlorethyl ether.separating the extract soluble therein from the ramnate insoluble indichlorethyl ether, mixing said raflinate with liquid propane andacetone, cooling said raflinate and separating the extract soluble insaid acetone from the Iafiinate insoluble therein. A v l .6. A processof separating parafiinoid and nonparafilnoid components from mineral oilcomprising mixing said oil with dichlorethyl ether, separating theextract soluble therein from the rafiinate insoluble in dichlorethylether, mixing liquid propane with said extract and dichlorethyl ether,and separating an insoluble raflinate and a soluble extract from saidmixture of propane,

dichlorethyl ether and extract from the first extraction.

7. A process of separating parafiinoid and nonparafiinoid componentsfrom mineral oil comprising mixing said oil with dichlorethyl ether,

separating the extract soluble therein from the rafiinate insoluble indichlorethyl ether, mixing liquid propane with said extract anddichlorethyl ether, reducing the temperature of said extract, andseparating an insoluble railinate and 'a soluble extract from saidmixture of propane, dichlorethyl ether and extract from the firstextraction.

8. A process of separating parafiinoid and nonparamnoid components frommineral oil which comprises extracting said oil in a first extractionstage with dichlorethyl ether, separating the rafiinate insoluble insaid ether from the extract soluble therein, reducing the temperature ofsaid extract, mixing liquid propane with said extract and dichlorethylether, separating the rafiinate insoluble in said second extractionstage from the extract remaining dissolved in said dichlorethyl ether,mixing acetone with the extract fromsaid second extraction stagedissolved in dichlorethyl ether, cooling said extract and separating therafilnate insoluble in said solvents from the extract soluble therein.

9. A process of separating parafiinoid and nonparafilnoidcomponents'from mineral oil which comprises extracting said oil in afirst extraction stage with dichlorethyl ether, separating the rafllnateinsoluble in said ether from the extract soluble therein, mixing acetonewith said rafiinate, reducing the temperature of said rafiinate,separating rafiinate insoluble in said second railinate extraction fromextract soluble in said acetone, mixing liquid propane with said extractand dichlorethyl ether from the first extraction stage, reducing thetemperature of said extract, separating rafilnate insoluble in saidsecond extract extraction from extract soluble in said dichlorethylether.

10. A process of separating parafiinoid and non-parafiinoid componentsfrom mineral oil which comprises mixing said oil with dichlorethylether, separating the extract soluble therein from the railinateinsoluble in dichlorethyl ether, reducing the temperature of saidextract to separate said extract into a second rafiinate and extract,separating said second rafiinate from said extract, cooling said secondrailinate, adding acetone to said second rafiinate, and separating therafflnate insoluble in said acetone from the extract soluble therein.

11. A process of separating parafilncid and non-.paramnoid componentsfrom mineral oil which comprises mixing said oil with dichlorethylether, separating the extractsoluble therein from the raflinateinsoluble in dichlorethyl ether, mixing liquid propane with said extract'and dichlor ethyl ether, reducing the temperature of said extract,separating a second rafiinate dissolvedin said liquid propane from theextract dissolved in dichlorethyl ether, mixing acetone with said secondraflinate dissolved in liquid propane, cooling said second raflinate,separating extract dissolved in said acetone from raiiinate undissolvedtherein.

12. A process of separating paraflinoid and non-parafllnoid componentsfrom mineral oil which comprises extracting said oil in a firstextraction stage with dichlorethyl ether, separating the rafiinateinsoluble in said ether from the extract soluble therein, mixing acetonewith said raifinate, reducing the temperature of said ramnate,separating raflinate insoluble in said second ramnate extraction fromextract soluble in said acetone, mixing liquid propane with said extractand dichlorethyl ether from the first extraction stage, reducing thetemperature of said extract, separating railinate insoluble in saidsecond extract extraction from extract soluble in said diincluding waxinsoluble therein, cooling said rafli-.

nate to precipitate the wax and separating the wax from the rafiinate.

DAVID R. MERRILL. PHILIP SUBKOW.

